Centrifugal screen



1,53 7,691 P. PRIEM Y CENTRIFUGAL. SCREEN Filed Aug. 16,, 1923 IN VENT 0/? ZWM ATTORNEY Patented May 12, 1925.

* UNITED fSTAT-ES -IPAUL'PRIEM, O'E'I-IEIDENI-IEIM,'GERIVLLANY, ASSIGNOR TO LKIvIERIUAN VD ITHCO NT ACT COMPANK'OZE? NEW' YORK, N. Y1,

A CUBPQEATION OF NEW YORK.

ceurmrueatsoensn.

Application filed au ust 16, 192a iSeria1:N'o.'657;'651.

:To all whom it may concern."

Be it known that :1, PAUL Pruner, a citizen of the :Republic of GerIna11y,'-and resident of IIGiClGl'll'lQilfl fl. d. 'Brenz, Germany, have invented ccrtainin'ew and useful flnn 'provements 'iirGentrifugal Screens of which the following :is a specification.

This :invention :relates "to centrifugal screens for operating on rmechanical pulp, chemical pulp, and other stocks mixed with 'liquidsl-and hasfor its niain object 'to complete a screening operation in=one machine and "to divide the screening effected in one machine .into S8V5B1i1'l steps, including both the screeningitself and the discharge of the screened stocl ,.so iastoobviate .theuse of pumps necessary in *connection'with the screening :mach'in es heretofore :used.

For adouble or multiple screen it "has been necessary v heretofore to arrange the screens on'difi'e'rent levels; so that the coarse pulp discharged from one iI'OW of machines can A be 'run by natural fall intothe "follow- *ing row, where itisdiluted-with'waterbefore being subjected to a repeated screening "action. e

lif the-screens are arranged on thesaine lev-el ithe'coarse pulp -dischaiged "from one row inust bezlifted byineans "offia pump into the following row of inrachines. The first "arrangement requires an extensive building *coinprising several stories; the second arrangement requires auxiliary apparatus including pumps and piping.

Both arrangements consume more "power than machines constructed 1 according to the present invention where the first and following screening ie-done =in'one and the same machine.

In the accompanying drawings is shown in vertical longitudinal section an em'loo'ch 1118M) of my invention. As illustrated 111 "thedrawin'gs, the n aln frame D of the machine is fPI'OVI'ClGd with an inlet A and with a perforated shell A The shell is also provided with a plurality of chambers or spaces a a and separated from each other by means of a transverse partition extending from the main frame to the perforzited screen.

The stock to be screened enters into the inlet Li which may be of any appropriate shape, and is thrown against-said screenby centrifugalnaetion 5 by *meansof a rota-ting space.

111111161"11101111t8Cl1IPOI1It shaft 6 and provided with wings =B The" shaft 6 is ij ournalled 1nsuitab1e bearings at end drivenvb'y a pulley b 111O1111l36d 'on said *tshaft. By

='1nea11s' of such operation part of the stock with fibres of acert'ain grade "of fin'en'ess passes 1 through the iperforations of the shell ni and passes into; the annular chamber a, l and then discharged therefrom through an outlet a connected with Sal'Cl Cli21-nl1b81f"01' The re1na1n1ng pai*ts of "the stock are carried 1n the dlrectlon 'o'f-thearrow -by rneans of the runner B and a'r e1nain--' talned'i'n a diluted stateby 'nieans ef water jets passing "from the apertures (if "a shower pipe 0 connected with a suitable source of supply.

The diSGharge fro-m "this shower pipe is spread over the entire inn'er surfac'e of theperforated shell A byineansof -a mantle I) provided with perforations and attached to thewings or the ru'nner B The finer parts-of the stock passthroirgh the perforations of the shell A into the ain 'n ular space or chamber (i provided with a discharge opening a". The coarser parts which cannot passthrough the"shell A are carried by the-tactlon o'f the runner through an overflow spout d yand pass from said spout into the second inlet A1 wherefthe 'stoc'lr is again diluted with 'w-aterentering the inlet from a 'suitable sourceo'f supply in the direction'of the-arrow y. o

'The diluted'coarse stock then "flows into the inner space of a perforated shell A*,

where it is subjectedfito the aotionfof a second runner provlded with wings 13 mounted upon the shaft Z7 and isthrown by the runner against the perforated'shell The-fine part-s ofthe stock pass through A*. the-perforations-ofthe shell 5A1 into anannular space or chamber formed in the easing and surrounding said "shell, and rare discharged froin said chamber through an outlet a while the r'elnainlngjcoarse stock is carried off fromthe shell the outlet spout a arranged frame D 1 i If it is desired to-deliver the coarse stock for a second screening operation, fheoutlet spout a can be arrangedlnore advantage- 2& through in the side 'ously in a *manner similar "to the overflow spout a on theuppenpart of "the see fraine D Theadvanta'ge of such-an arrangement consists in the fact that a pump for lifting the stock to a second screen on the samelevel as the first can be dispensed with.

The perforations of the shell A A and A" may be made of the same size, or of different sizes relatively to each other, according to the grade of pulp to be screened.

In contrast to the known devices heretofore used, the above described invention has the advantage that the separate materials received from the discharge opening a a,

a are of greater uniformity. Further-.

more, the material at itsdischarge from the opening a is again thoroughly mixed with water by means of the water jet supply pipe C in consequence whereof the fine particles separate themselves better from the coarser particles. In addition thereto, the separate water discharge pipes in the inner part of the round sievein the described third step through the sieve A provide a more complete separation or division ofv the fine material present.

In contrast to the known processes, the advantage of this invention over the prior devices used resides in its greater simplicity; since by the'present invention a single machine is used with a single shaft, and only one power transmission is necessary, saving immaterial, space, and power. v

I have describedan embodiment of my invention, butit is clear that changes may be made without departing from the scope of the invention as defined in the appended claims. a

'VVhat Ielaim as new and desire to secure by Letters Patent is:

1. In a centrifugal screen, the combinationof a casing provided with a pluralityof chambers arranged axially of said casing, a

cylindrical screen forming the inner wall of said chambers, and a runner mounted upon a shaft axially ofsa d screen and provided with wings extending opposite to the wall of said screen and the chambers of-said casing.

2. In a centrifugal screen in combination with an outside shell, a shaft with bearings outside of the shell, a runner with wings fastened to the shaft, a second runner of similar design fastened on the sameshaft, a per- ;forated shell surrounding each of therunners, means dividing the space between the outside shell and perforated shell into 'com partments, a stock inlet feeding the stock to compartments, a stock inlet feeding the stock to be screened to the first runner, means for transporting the stock from the first runner into the following runner, and means for diluting the stock before it passes from one zone of the perforated shell into the other.

l. In a centrifugal screen, in combination with an outside shell, a shaft with bearings outside of the shell, a runner with wings fastened to the shaft, a second runner of similar design fastened on the same shaft, a perforated shell surrounding the runners and divided into several zones, a stock inlet feeding the stock to be screened to the'first runner, an overflow spout for the stock in the partition wall of the zones of the perforated shell, arranged on the upper part of the screens, and means for transporting the stock tobe screened through the overflow spout. I

5. In a centrifugal screen, in combination with an outside shell, a shaft with bearings outside of the shell, a runner with wings fastened to the shaft, asecond runner of similar design fastened on the same shaft, a perforated shell surroundingthe runnersand divided into several zones, a stock inlet feeding the stock to be screened to the first runner, an overflow spout for the stock in the partition wall of the zones of the perfo rated shell, arranged on the upper part of the screen, a second inlet into which the stock is discharged from the overflow spout, and

I means for discharging the stock through the overflow spouts 7 6. In a centrifugal screen, in combination with an outside shell, a shaft wlthbearings on the outside of the shell, a runner withwings fastened on the shaft, a second runner of similar design fastened on the same shaft, a perforated shell surrounding the runners and divided into several zones, a stock inlet feeding the stock to bescreened to the first runner, an overflow spout for the stock in'the'partition wall of the zones of the perforated shell, arranged onthe upper part of thesereen,'a second inletinto which the stock is discharged from the overflow spout, a water connection to the second inlet-for, diluting the stock, and means for transporting the stock from the overflow spout 1 7. In a centrifugal screen, in combination with an outside shell, a shaft with bearings on the outside of the shell, a runner with V wings fastened to the shaft, a second runner of simllar design fastened on the same shaft,

a perforated shell surrounding the runners and divided into several zones, a stock inlet feeding the stock to be screened to the first runner, an overflow spout for the stock in the partition wall'of the zones of the perforated shell, arranged on the upper part of the screen, a second inlet into which the stock is discharged from the overflow spout, a Water connection to the second inlet for diluting the stock, a discharge spout on the end Wall of the last zone of the perforated shell, and means for transporting the coarse stock through this discharge spout.

8. In a centrifugal screen, having a per forated shell, an outer casing divided into different discharging zones, corresponding to different zones ofthe perforated shell.

9. In a centrifugal screen having a perforated shell, an outer casing divided into different discharging zones, corresponding to different zones of the perforated shell, a rotary blade Within the perforated shell, and water supplying means for the rotary blade to enable Water to be supplied to the stock and both moved by the blade to zones after and free of the first zone, for diluting the stock discharging against the shell after the first zone.

10. In a centrifugal screen having a perforated shell, an outer casing divided into different discharging zones corresponding to different zones of the perforated shells, and separate conduits communicating with the separated zones for conducting away the separated stocks. I

11. In a centrifugal screen having a perforated shell, an outer casing divided into separate discharging compartments, With a shell forming one wall thereof, a rotary blade within the shell and easing, a perforated Wall movable with the blade and arranged free of the first compartment, and Water supplying means for the perforated Wall, whereby Water is supplied to the stock by said perforated Wall after the first compartment.

In testnnony that I claim the foregoing as my invention, I have signed by nameh'ereunder.

PAUL PRIEM. 

